I'm unsure of the narrative that Gothic civilization was the birth of high German and an origin for mongrelization of the German people. My understanding from l

I'm unsure of the narrative that Gothic civilization was the birth of high German and an origin for mongrelization of the German people. My understanding from lots of other sources of ancient history was that the Germanic heartland and the eastern Gothic offshoot evolved quite distinctly, with tenuous connections through Germanic settlements throughout Hungarian, Romanian, and Polish lands (which MAY amount to a language continuum, I'm unsure). My impression is that High German evolved fairly distinctly in the Bavarian and Austrian heartlands during the age of the Holy Roman Empire, while Gothic populations were assimilated by Slavic, Bulgarian, and Romanian peoples and were eventually absorbed until the Gothic language went extinct.